Synthetic resin bottles are in wide use as the containers for various liquid contents. These bottles are molded by using blow molding or biaxial-drawing, blow-molding means.
This synthetic resin bottle has an advantage of lightweight. On the other hand, because of bulkiness and large space of occupancy, a problem of high storage and transportation costs are caused during the process in which bottles are molded by the bottle manufacturers, delivered to product manufacturers, and filled with liquids. Handling of bulky bottles is also troublesome.
After use, the used bottles are usually flattened with hands or feet to reduce the volume of the bottle and to facilitate waste disposal. The bottles had a problem in that everyone cannot always flatten bottles easily and steadily.
Utility model laid open No. 1985-75212 describes a technique aimed at easily flattening bottles at the time of waste disposal.
The synthetic resin bottle described in this utility model is provided with a pair of ribs at the axisymmetric positions on the body. In addition to these ribs, arc ribs are also provided on the shoulder and at the lower end of the body. When the bottle is put to waste disposal, the portion surrounded by the ribs is pressed to let the body cave in and deform so that volume reduction can be achieved.
However, in this conventional art, the concaved portion ranges from the shoulder to the lower end of the body, with neck and bottom retaining the original shapes. Because of this limitation, the bottle had trouble in that the entire bottle cannot be pressed flat and deformed. Since these ribs are aimed at flattening the bottle at the time of waste disposal, it was almost impossible to restore the original shape of the bottle once the bottle has been forced to cave in.
This invention has thus been made to solve the problems of the above-described conventional art. The technical problem of this invention is to deform the bottle easily in a volume-reducing manner until the bottle is fully flat and then to be able to restore the original shape as a bottle from the flat or concaved state. Thus, an object of this invention is to make bottle handling easy and efficient during the process from molding to the filling of bottles with contents and at the time of bottle disposal as waste, and the reduction of the cost.